(
bag-count
[
procedure?
predicate
]
[
bag?
bag
]
)
⟹
integer?

predicate
⟹
(
Î»
obj
)
⟹
boolean?

(
bag-count
[
procedure?
predicate
]
[
bag?
bag
]
)
⟹
integer?

predicate
⟹
(
Î»
obj
)
⟹
boolean?

(
boolean-hash
obj
)
⟹
integer?

boolean-hash, char-hash, char-ci-hash string-hash, string-ci-hash, symbol-hash, number-hash These are hash functions for some standard Scheme types, suitable for passing to make-comparator. Users may write their own hash functions with the same signature. However, if programmers wish their hash functions to be backward compatible with the reference implementation of SRFI 69, they are advised to write their hash functions to accept a second argument and ignore it. These are suitable hash functions for the specified types. The hash functions char-ci-hash and string-ci-hash treat their argument case-insensitively. Note that while symbol-hash may return the hashed value of applying symbol->string and then string-hash to the symbol, this is not a requirement.

(
boolean-hash
obj
)
⟹
integer?

(
bytevector-length
[
bytevector?
bytevector
]
)
⟹
integer?

Returns the length of bytevector in bytes as an exact integer.

(
bytevector-u8-ref
[
bytevector?
bytevector
]
[
integer?
k
]
)
⟹
integer?

It is an error if k is not a valid index of bytevector. Returns the kth byte of bytevector.

floor, ceiling, truncate, round These procedures return integers. The floor procedure returns the largest integer not larger than x. The ceiling procedure returns the smallest integer not smaller than x, truncate returns the integer closest to x whose absolute value is not larger than the absolute value of x, and round returns the closest integer to x, rounding to even when x is halfway between two integers. Rationale: The round procedure rounds to even for consistency with the default rounding mode specified by the IEEE 754 IEEE floating-point standard. Note: If the argument to one of these procedures is inexact, then the result will also be inexact. If an exact value is needed, the result can be passed to the exact procedure. If the argument is infinite or a NaN, then it is returned.

Given a Unicode character, char->integer returns an exact integer between 0 and #xD7FF or between #xE000 and #x10FFFF which is equal to the Unicode scalar value of that character. Given a non-Unicode character, it returns an exact integer greater than #x10FFFF. This is true independent of whether the implementation uses the Unicode representation internally. Given an exact integer that is the value returned by a character when char->integer is applied to it, integer->char returns that character.

(
char-ci-hash
obj
)
⟹
integer?

(
char-ci-hash
obj
)
⟹
integer?

(
char-hash
obj
)
⟹
integer?

(
char-hash
obj
)
⟹
integer?

(
comparator-hash
[
comparator?
comparator
]
obj
)
⟹
integer?

Invokes the hash function of comparator on obj and returns what it returns. More convenient than comparator-hash-function, but less efficient when the function is called repeatedly. Note: No invokers are required for the equality and ordering predicates, because =? and <? serve this function.